Sunday, August 22, 2010

Motorcycle Deaths On Wisconsin Roads Trending Higher

It feels like there's been a lot of fatal motorcycle accidents in Wisconsin recently.

Two data sets from the Wisconsin Department of Transportation support that thesis.

I'd thought I was just an obsessive, selective reader of the Journal Sentinel's News Watch service, but this very sort of report about a biker's death seemed like a frequent story these last few months.

Or this one.

Or this most recent one.

So a couple of weeks ago I asked the Wisconsin Department of Transportation for their up-to-date figures, and what I got back from the agency began to bear out my hunch:

Through the first seven months of the year - - January to July - - there had been 61 motorcycle fatalities on Wisconsin roads.

in most of the recent years in the data WisDOT supplied dating back to 2004, the number for the same January-July time frame is generally lower.

Here are the numbers also for the same seven-month period of time back to 2004: remember that for 2010, the number is 61:

2009 - - 56; 2008 - - 44; 2007 - - 67; 2006 - - 60; 2005 - - 53; 2004 - - 46.

Then I found separate, more up-to-date WisDOT data through August 15 on this web page that shows the number of all traffic crash deaths in Wisconsin this year so far virtually unchanged from last year - - but motorcyclist driver deaths are up for that January - - August 15 period over the same time frame in 2009 by almost 20% - - 65 as opposed to 56.

Now I'm not a statistician, and someone can jump in here and tell me that the number of years in the sample is too small, or there are variations in how the data is reported, or the differences are statistically insignificant, but regardless, I'd interpret the data this way:

The seven-month fatality total in 2010 exceeds the average of 55 for that time frame as supplied by WisDOT, a difference of about 10%.

So while 61 fatalities is not the highest total in the WisDOT-supplied sample for the January-July time frame - - the most is 67 fatalities, in 2007 - - the 61 fatalities between January and July is trending in the wrong direction.

It's not clear if we are on a pace to exceed the annual total of 110 deaths recorded in 2007- - the highest of all the years in the sample - - and let's hope not.

The lowest total annual fatality total in the sample, between 2004 and 2009, was 81 in 2004.

Maybe it's our recent run of warm days. Or wet days? I don't know.

Could be bad luck on top of what usually is involved - - various operator errors by the motorcyclist and other drivers, speed, alcohol, etc.

I'm not casting blame - - just reporting official numbers that, at a minimum, suggest that everyone on the roads needs to be more careful.

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